Passwords have protected business accounts for decades, but they also create a persistent security problem. Users need to remember them, attackers can phish them, breaches can expose them, and password reuse can turn compromise of one service into risk for another.

Adding multi-factor authentication makes passwords much harder to abuse, yet many traditional MFA methods still ask users to recognise fraudulent login pages, protect one-time codes or judge whether an approval prompt is legitimate.

Passwordless authentication changes the model. Instead of asking the user to provide a reusable secret, technologies such as passkeys and FIDO2 security keys use cryptographic credentials that prove possession of an authenticator without revealing the credential attackers would normally try to steal.

The UK’s National Cyber Security Centre now recommends passkeys over passwords where services support them, reflecting a broader move towards phishing-resistant authentication. For businesses, the opportunity goes beyond removing password frustration. Passwordless access can reduce credential theft, eliminate password reuse and make common phishing techniques significantly less effective.

However, passwordless does not remove every identity risk. Organisations still need to protect enrolment, recovery, endpoints, privileged accounts and any legacy authentication methods that remain available alongside the new approach.

What Is Passwordless Authentication?

Passwordless authentication allows a user to prove their identity without sending a traditional password to the service during sign-in.

Passkeys and FIDO2 security keys achieve this through public-key cryptography. The service stores a public key, while the user’s authenticator holds the corresponding private key. During authentication, the authenticator proves possession of that private key without sending it to the website or application.

This creates an important security difference.

A password is a reusable secret that the user knows and can accidentally disclose. A cryptographic credential does not require the employee to type or communicate the underlying private key, so a fake login page cannot simply collect the credential in the same way it captures a password or one-time code.

Modern passwordless systems often combine possession of the authenticator with local user verification. A user might unlock a passkey with a fingerprint, face recognition or device PIN before the authenticator completes the cryptographic sign-in.

The current NIST authentication guidance recognises FIDO2 and WebAuthn-based authentication as phishing-resistant because the authentication process binds the credential to the legitimate service.

Passwordless authentication therefore does not simply remove a text box from the login screen. It changes how the user proves identity.

How Passkeys and Security Keys Work

Passkeys and physical security keys share much of the same cryptographic foundation, but they handle credentials differently. That distinction matters when businesses decide how to protect ordinary employees, administrators and high-value accounts.

1.    Passkeys Replace Reusable Passwords with Cryptographic Credentials

When a user creates a passkey, their authenticator generates a cryptographic key pair for the account.

The service receives the public key, while the authenticator protects the private key. When the employee later signs in, the service sends a cryptographic challenge and the authenticator proves possession of the correct private key.

The private key does not need to travel to the service.

Passkeys also bind authentication to the legitimate website or application. If an attacker sends an employee to a fake sign-in page, the passkey does not simply produce a reusable code that the attacker can relay elsewhere.

This property addresses one of the weaknesses discussed in multi-factor authentication security, where manually entered OTP codes and some approval-based methods can still fall victim to phishing or real-time relay techniques.

2.    Synced Passkeys Improve Convenience Across Devices

Many passkeys can synchronise through a user’s credential manager so that the person can use the same account across multiple trusted devices.

For example, an employee may create a passkey on one device and later use it from another device connected to the same credential ecosystem. This improves usability because the employee does not need to create and manually manage a different password for every service.

NIST’s current Digital Identity Guidelines explicitly accommodate syncable authenticators, including synced passkeys, for appropriate authentication scenarios. The guidance also emphasises protecting the systems that store and synchronise those credentials.

Businesses should therefore consider the security of the credential manager or sync account as part of the overall authentication design. Moving away from passwords does not mean ignoring the account that controls access to synchronised credentials.

3.    Device-Bound Credentials Keep the Key on One Authenticator

Some organisations prefer credentials that remain tied to a particular device rather than synchronising across a broader ecosystem.

A device-bound credential can offer tighter control because the private key stays on one trusted platform or authenticator. Businesses may find this model attractive for privileged administration or environments where they need greater assurance about which device holds the authentication credential.

The trade-off involves recovery and availability.

If the device fails or disappears, the user may lose access unless the organisation has already registered another authenticator or established a secure recovery process.

This makes device-bound credentials particularly suitable where the security benefit justifies more deliberate credential management.

4.    Physical Security Keys Provide a Separate Hardware Authenticator

A FIDO2 security key stores authentication credentials on a dedicated physical device.

The employee inserts or connects the key, then typically performs a physical action and may enter a PIN or use another local verification method. The security key completes the cryptographic authentication with the legitimate service.

Physical keys can work particularly well for administrators and other high-risk users because they keep the authentication credential on separate hardware and require deliberate user interaction.

The NCSC guidance on recommended MFA methods places FIDO2 credentials, including trusted platform authenticators and roaming security keys, among the strongest authentication options for organisations.

Businesses still need a process for lost or damaged keys. Registering suitable backup authenticators can prevent emergency recovery from becoming a weaker route into the account.

Why Passwordless Authentication Can Reduce Business Identity Risk

The most important benefit of passwordless authentication comes from removing the reusable credential that many attackers target.

Phishing provides a clear example. A fake website can ask someone to enter a password, SMS code or authenticator OTP. A passkey does not provide the user with an equivalent reusable secret to type into that fraudulent site.

Password reuse also disappears for accounts that genuinely remove passwords. Each service receives a different cryptographic credential, so compromise of one service does not expose a password that attackers can test against another.

Credential stuffing consequently becomes far less relevant. Attackers cannot take lists of previously breached passkeys and replay them across unrelated sites in the same way they test username and password combinations.

The NCSC’s 2026 analysis of passkeys and FIDO2 credentials concluded that these credentials resist phishing and provide security advantages over traditional password-plus-MFA approaches across common attack scenarios.

Usability can improve at the same time. Employees no longer need to invent, remember and repeatedly enter passwords for supported services. Reducing authentication friction can also lower the temptation to reuse credentials or rely on weak password-management habits.

These advantages strengthen the broader goal of protecting user accounts from compromise, but passwordless authentication should still operate alongside appropriate access rights, endpoint protection and monitoring.

Passkeys vs Security Keys vs Password-Based Authentication

Different authentication methods provide different combinations of security, convenience and operational control.

Authentication Method

Phishing Resistance

Main Advantage

Important Consideration
Password only No Works almost everywhere Vulnerable to phishing, reuse, guessing and credential theft
Password + OTP MFA No Adds meaningful protection over passwords alone Users can still enter passwords and codes into phishing sites
Password + push MFA Depends on implementation Convenient for users Social engineering and approval abuse can remain possible
Synced passkey Yes, when correctly implemented Strong security with convenient cross-device access Organisation must consider credential-manager and recovery security
Device-bound FIDO2 credential Yes Strong control over where the credential resides Device loss requires suitable backup or recovery
Physical FIDO2 security key Yes Strong phishing resistance and separate hardware Key distribution, backup and replacement require management

The right answer does not always involve choosing one method for every employee.

A general workforce may benefit from convenient passkeys that work across managed devices, while administrators could use device-bound credentials or physical security keys for higher-risk access.

Legacy applications may continue to require passwords and MFA until the organisation replaces or modernises them. That creates a transitional environment where passwordless authentication strengthens some access paths while older authentication still needs careful protection.

The business should judge success by whether attackers still have an easier fallback route. Deploying passkeys for a cloud service provides limited benefit if users can bypass them through an older password-only authentication method attached to the same account.

Where Passwordless Authentication Can Still Go Wrong

Passkeys remove major password-related attack paths, but they do not make identity security automatic. Poor recovery, insecure devices and weak enrolment processes can still undermine strong authentication.

1.    Weak Recovery Can Become the New Target

Attackers adapt to the easiest remaining route.

If they can no longer steal a password, they may try to manipulate the process used when an employee loses a device or needs to replace an authenticator.

A business might deploy phishing-resistant passkeys while allowing the helpdesk to reset authentication after a weak identity check. In that situation, attackers can focus their social-engineering effort on support staff instead of the login page.

Recovery therefore needs security proportional to the account.

Privileged users and high-impact accounts may require stricter identity verification before teams remove or replace authenticators. Organisations should also monitor unusual recovery activity and new credential registration.

2.    Compromised Devices Still Matter

A passkey can resist phishing without making the endpoint itself trustworthy.

Malware operating on an employee laptop may attempt to steal information, manipulate the user’s activity or abuse access after authentication succeeds. A compromised endpoint can also expose active sessions even when attackers cannot extract the passkey itself.

This means passwordless authentication should strengthen endpoint security rather than replace it.

The relationship between user identity and endpoint condition becomes especially important under Zero Trust endpoint security, where access depends on both who the user is and whether the device provides enough assurance for the requested resource.

3.    Poor Enrolment Can Bind the Wrong Authenticator to an Account

Authentication becomes trustworthy only if the organisation securely establishes which authenticator belongs to which user.

Weak enrolment creates an opportunity for attackers to register their own credential against someone else’s identity.

Businesses should therefore protect the initial credential-registration process and treat the addition of new authenticators as a security-sensitive event. Higher-risk accounts may justify stricter verification or administrative oversight.

Monitoring can help here as well. An unexpected passkey or security-key registration should provide enough context for security teams or users to recognise and challenge unauthorised changes.

4.    Password Fallback Can Preserve the Original Weakness

Some services allow passkeys while keeping passwords available as an alternative login method.

That approach can make migration easier, but it also means attackers may continue targeting the weaker route.

If a user can sign in with either a phishing-resistant passkey or a phishable password plus weak MFA, the account has not fully removed password risk.

Businesses should understand which fallback methods remain available, why they exist and whether the organisation can progressively restrict them once users have reliable passwordless access.

The same principle applies to legacy protocols and applications. Passwordless authentication delivers its greatest value when businesses remove or tightly control weaker parallel authentication routes.

How Businesses Should Introduce Passwordless Authentication

A passwordless rollout should begin with the accounts and applications where stronger authentication provides the greatest value.

Privileged users make a logical starting point because compromise of their accounts can create much greater business impact. Administrators can use FIDO2 security keys, device-bound credentials or other phishing-resistant methods appropriate to the environment.

Business-critical services should follow where platform support allows it. Email, identity providers, cloud administration and systems containing sensitive information often deserve priority because attackers gain substantial value from compromising those accounts.

User experience also matters. Passkeys can simplify authentication, but employees need to understand what has changed, how they enrol devices and what to do if they lose access. Clear processes reduce support pressure and discourage unsafe workarounds.

Organisations should test recovery before large-scale deployment. Security teams need to know how an employee regains access after losing a device without introducing a recovery mechanism that attackers can exploit more easily than the original authentication.

Device management forms another part of the decision. Synced credentials may suit much of the workforce, while high-risk roles may require more control over where credentials reside. Businesses should choose according to account sensitivity rather than assuming one model fits every user.

Existing MFA should also remain in place where passwordless support does not yet exist. Migration should strengthen authentication progressively rather than create gaps during transition.

Finally, businesses need to review authentication alongside the rest of their identity environment. An identity and endpoint security posture assessment can help identify legacy authentication, excessive privileges, unmanaged endpoints and recovery weaknesses that could reduce the benefit of a passwordless deployment.

Aegixis Identity & Endpoint Security Services can support organisations that need to strengthen authentication alongside privileged access, endpoint security, least privilege and wider identity controls.

Final Thoughts

Passwordless authentication addresses one of the oldest weaknesses in business security by removing the reusable secret that attackers have spent decades learning to steal. Passkeys and FIDO2 security keys make phishing significantly harder because authentication depends on cryptographic proof tied to the legitimate service rather than information the user can accidentally hand to an attacker.

The strongest rollout still looks beyond the login itself. Businesses need secure enrolment, trustworthy endpoints, resilient recovery and appropriately limited permissions around every passwordless account. Done well, passwordless authentication does more than make sign-in easier. It removes entire attack techniques from the identity-security problem.